android - How can I retrieve shared preferences onCreate? -

in preferences change preference view according unit type(imprial or metric). on create method checking last value of measurement_unit preference, return metric on app startup. have onsharedpreferencechangelistener changing view according user entry, working. how can saved preference when oncreate called?

public class prefmainactivity extends preferenceactivity{     string tag="blueglucose";    @override   public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);          actionbar actionbar = getactionbar();         actionbar.setdisplayhomeasupenabled(true);           actionbar.settitle(r.string.action_settings);          this.init_view();      }    @override   public boolean onoptionsitemselected(menuitem item) {          switch (item.getitemid()) {           case android.r.id.home:               finish();               return true;            default:               return super.onoptionsitemselected(item);       }   }    sharedpreferences.onsharedpreferencechangelistener spchanged = new           sharedpreferences.onsharedpreferencechangelistener() {              @override             public void onsharedpreferencechanged(                     sharedpreferences sharedpreferences, string key) {                               prefmainactivity.this.init_view();              } // stuff here };       private void init_view(){            try         {             sharedpreferences prefs = preferencemanager.getdefaultsharedpreferences(this);             string metric = getresources().getstring(r.string.imperial);              if (prefs.getstring("measurement_unit",metric)  == metric)                 getfragmentmanager().begintransaction().replace(android.r.id.content,                     new prefmainfragmentimperial()).commit();             else                 getfragmentmanager().begintransaction().replace(android.r.id.content,                         new prefmainfragmentmetric()).commit();               prefs.registeronsharedpreferencechangelistener(spchanged);         }         catch(exception ex)         {          }     } 

        if (prefs.getstring("measurement_unit",metric)  == metric) 

string in java need compared equals or equalsignorecase